In some toner formulations, including some emulsion aggregation (EA) toner formulations, some chemical toners, and some conventional toners, the toner particles are treated with one or more surface additives (herein “surface additive”), such as a charge control agent, to form surface-treated particles comprising a parent particle having an outer surface to which surface additive is adhered. In some cases, the charge of the toner particles before being treated with surface additive is higher than that of the final surface additive-treated toner particles. Thus, the charge of the parent particle surface is higher than the charge of the surface-treated toner particles. Depending on the development system and the toner age, this characteristic can lead to charge instability, which can then lead to density variation and limited toner gamut in color toners. This charge instability is the result of increasing exposure of the higher-charged parent particle surface over time due to surface additive being rubbed off of the particle surface, being transferred to the carrier, such as in the case of two component development (TCD) systems, and/or the surface additive being impacted into the particle.